Newest Firefox - Greasemonkey

There is a fix being rolled out now - Mozilla identified the problem and are correcting it. They say to NOT delete or change anything and fix will automatically happen.

Tampermonkey is so much better —they have a working Import feature & a ton of customization options —let's face it, Greasemonkey is ancient & archaic. My FF got wiped out & I couldn't Import through Greasemonkey from Opera (where I also use TM), so I was forced to switch… Also I use Stylus instead of Stylish, which was rocked by many privacy breaches; so far so good. I used to be a Greasemonkey\ Stylish fan too, but they haven't updated or delivered anything new… I use Firefox Developer Edition.

greasemonkey and theme is disabled for me. Also I can't download other alternatives. Says internet unavilable...

Mine is disabled as well and there appears to be no way to enable while accepting whatever risk it is they think they are protecting us from.

For me appear like active: http://prntscr.com/nkfqn8 & http://prntscr.com/nkfrm1

Players who use Firefox have to check if this setting is on - to have the automatic fix about disabled addons. After a short time, the temporary fix will disable the problematic - Certificate validation - function. They work on a final fix...
prntscr.com/nkczpg

Looks like they fixed it, mine is back to normal without my having to do a thing. Don't you just love updates like this?

Where it is fixed without any intervention, "installing and running studies" was enabled in settings.
- I am not sure about the future of addons in Firefox, but they are said to be disabled soon. So, we could try now what it will be like later.

Ver. 66.0.5 of Firefox has fixed the problem...